In conventional C-wrap type tissue formers the outer forming fabric is separated from the web and the inner forming fabric at a position on the forming roll or slightly downstream thereof. Carried by the inner forming fabric the web runs to a pick-up location, where a looped felt or other fabric is brought into contacting relationship with the web, and the web is transferred to the felt. Downstream of the pick-up location the felt with the web is trained around a press roll, which lightly presses the web against a yankee dryer and transfers the web to the yankee dryer. After drying on the yankee dryer the web is creped off and-run to a web reeling apparatus.
It is generally accepted that through air drying of tissue as disclosed in U.S. Pat. Nos. 3,301,746 (Sanford et al.), 3,303,576 (Sisson), 3,821,068 (Shaw), 4,102,737 (Morton), 4,440,597 (Wells et al.), and 4,481,722 (Guy et al.), for example, greatly enhances product softness, bulk and absorbency. While much effort is spent creating and restoring these characteristics to the conventionally manufactured products, softness and absorbency are inherent in the through air process. What has been less appreciated is the underlying economics behind the through air dried soft tissue manufacturing process. However, bearing in mind that the basis for consumer usage is the area of the tissue product and not the weight, and that to a customer a single-ply TAD product is at least equivalent to a conventionally produced two-ply product, a comparison can be summarized as follows:
1. The ability to manufacture a product using less raw material (reduced basis weight) with the TAD process results in significant cost savings over a market equivalent sheet manufactured on a conventional machine. PA1 2. Energy costs, when examined on the basis of area of saleable product, are actually less for the products made on a TAD machine. PA1 3. The combined effect of less cost per unit area of product produced and increased production rates, makes the economics of through air dried products very favorable in comparison to conventionally manufactured products.
The above advantages of the TAD technology have resulted in an increasing interest of tissue mills in rebuilding conventional tissue machines to TAD machines, substantially as outlined above, which has required the incorporation of a transfer section having a transfer fabric for picking up the web from the inner forming fabric and transferring the web to the TAD fabric that replaces the felt. The incorporation of a transfer section increases the rebuilding costs as well as the total number of sheet transfers, which increases fiber losses and reduces overall efficiency.